Fast Set Non-Shrink Leak Seal Compound

Product Description

A one-part, cement based, fast set plugging mortar for stopping active water infiltrations. When mixed with water it forms a plastic, highly workable mortar which can be applied by hand to plug leaks in concrete and masonry structures.


  • Sealing active water leaks and seepage through cracks, non-moving joints, honeycombing and holes in concrete, masonry, and stone
  • As a preparation to seal concrete cracks/non-moving joints prior to carrying out waterproofing resin injections


  • Fast setting time for instant plugging of leaks
  • Can be applied directly to wet surfaces
  • Strong bond – Resists washout under active water pressure
  • Simple “add water, mix and pack” application
  • Low VOC – <10 gram/litre TVOC
  • Compatible with concrete and masonry
  • Does not produce efflorescence
  • Does not contribute to steel corrosion

System Components

BETEC™ Waterstop Plug – 1-part, fast cure, cementitious plugging mortar

CRYSTALSEAL™ – 1-part, cementitious crystalline growth compound for secondary sealing of damp concrete surfaces


Generally, suitable for dry, wet, damp or dampened cracks, non-moving joints in vertical and horizontal concrete, masonry and stone (subject to site adhesion test to specific stone involved).

Compatibility / Adhesion

BETEC™ Waterstop Plug may be applied to the following cured, stable, prepared substrates:

  • Poured in-situ and pre-cast concrete, blockwork, brick
  • Concrete masonry, blockwork
  • Most unglazed brick (test adhesion before use to confirm)
  • Most stone (test adhesion before use to confirm)

Substrate Quality

Substrates must be structurally sound and clean.

New Concrete

Well compacted, cured 28 days, dependant on concrete thickness.

Curing and Form Release Compounds

Only non-permanent, degrading acrylic types may be used. Residues must be removed by water blasting or grinding prior to priming. Wax emulsion, oil, hydrocarbon, hydrocarbon resin, chlorinated rubber, silicon containing or bitumen emulsion types are unacceptable.

Concrete Strength

Compressive Strength - minimum 25 MPa.

Tensile Strength – minimum 1.5 MPa.

    Substrate Preparation

    Concrete, Masonry, Brick and Stone

    Remove all dirt, dust, weak or damaged concrete, laitance, oil, grease, coatings, curing compounds, form release agents, mould, algae and other contaminants which could adversely affect adhesion by an appropriate method. This may include brooming, scraping, water blasting (4000 psi with RotorJet head), captive or grinding.

    Advise main contractor of identified structural cracks and moving construction joints. Rectifications to be arranged by main contractor.

    Chase cracks, non-moving construction/cold joints and holes to a minimum width and depth of 20mm and clean away dust/slurry with clean water. Do not form “V” chases. Undercut sides of chase to maximise binding strength of the BETEC™ Waterstop Plug.

    Pre-wet all substrates thoroughly with clean water until the substrate is saturated.

    Application Conditions

    The following GCP product application details assume typical conditions of 22°C and 60% relative humidity. Allowance must be made by the applicator for product application and cure times that vary from these typical conditions. BETEC™ Waterstop Plug will cure more slowly in cold weather and rapidly in warm weather.

    Parameter Limits
    Substrate Temperature +5°C to +35°C
    Ambient Temperature +5°C to +35°C
    Relative Humidity 10% to 98%
    Condition Clean, damp and free from contaminants



    BETEC™ Waterstop Plug has a workability time of less than 1 minute at 22°C. Only mix the product immediately before installation.

    Wear protective rubber gloves, eye protection and a dust mask during all handling, mixing and installation processes, in accordance with the current SDS for BETEC™ Waterstop Plug.

    The specified mix ratio of 3:1 (by weight) must be adhered to:

    3 Parts BETEC™ Waterstop Plug : 1 Part Water

    Mix only small amounts of BETEC™ Waterstop Plug at a time. eg. - 300 grams BETEC™ Waterstop Plug : 100 grams Water.

    Addition of excess water will reduce strength of the cured product.

    Only use clean, fresh water with BETEC™ Waterstop Plug.

    In warm weather, use cold water to extend workability time of the mixture.


    To a clean plastic container, add the required amount of clean water.

    To assist with mixing, round, bowl-like plastic containers provide the best results.

    Add the required amount of BETEC™ Waterstop Plug powder to the container and mix using a gloved hand for approximately 15 seconds, until a smooth putty like consistency is achieved.

    The mixture will become slightly warm during mixing.


    Apply the mixed BETEC™ Waterstop Plug when it is stiff, but still plastic.

    Press the material into the chase/cavity and keep in place by exerting pressure with a gloved hand until the mortar has set and become solid.

    Do not move the mortar during the setting phase.

    Do not release pressure too quickly. The mortar must be allowed to develop sufficient strength to withstand the water pressure.

    At internal corners (wall-slab, wall-wall joints) form the mortar into 45° fillets.

    The mortar may be applied in several layers, especially when applying to large voids.

    In some cases it may be required to use plastic drainage tubes to release water pressure during application of the mortar. Once the repair is set, remove the tube and plug hole with mortar to fully seal off water flow.

    Due to rapid hydration, BETEC™ Waterstop Plug will develop a high temperature during cure. To prevent rapid loss of water, dampen the hardening mortar with clean water for approximately 15 minutes after application.

    If dampness of substrate surrounding the repair persists, it may be sealed by application of a slurry coat of CRYSTALSEAL™ 1-part, cementitious crystalline growth compound.

    Clean up

    Clean application equipment immediately using clean water. Hardened product must be removed mechanically.

    Supply and Packaging

    Product Package Size
    BETEC™ Waterstop Plug 15 kg pail
    CRYSTALSEAL™ 12.5 kg pail


    Application rates are dependent on type and size of repair. As a guide, a typical 20mm x 20mm chase will require a minimum 1.3kg of mixed BETEC™ Waterstop Plug per meter of chase length, or 0.975kg of BETEC™ Waterstop Plug powder and 0.325kg of water, not including wastage.


    Product should be stored in original packaging at temperatures between 10° and 35°C, under cover and protected from all sources of heat, ignition, moisture, frost and direct sunlight.

    Shelf Life

    Twelve (12) months from date of manufacture when stored in original, unopened packaging, in accordance with storage conditions detailed above.

    Typical Properties

    Unmixed Product Properties

    Property Typical Value
    Appearance Dark grey powder
    Particle Size (mm) 0 to 1.0

    Mixed Product Properties

    Property Typical Value
    Appearance Dark grey, with putty like consistency
    Mix Ratio
    BETEC™ Waterstop Plug : Water
    3 : 1 (by weight)
    Mixed Mortar Density (kg/m3) 2150
    Working Time @22°C (seconds) 30
    Setting Time @22°C (seconds) 60
    28 Day Compressive Strength (MPa) 30

    The above values and properties do not constitute a specification

      Shelf Life

      Stored in a cool, dry place unopened or resealed pails have a shelf life of 1 year from date of manufacture.

      Health and Safety

      For all GCP products, read the product label and Safety Data Sheet (SDS) before use.

      Always wear PPE detailed in the SDS for this product and comply with all risk and safety phrases detailed. SDS is readily available from GCP Applied Technologies.


      Cementitious materials can lead to incompatibilities under certain conditions in combination with non-ferrous metals such as aluminium, copper, zinc etc.

      Low temperatures delay the setting of this material.

      High temperatures accelerate the setting and decrease the working time of this material.

      Unsuitable for sealing water ingress at moving joints or active cracks.

      Unsuitable for structural repair to structural cracks etc.


      GCP and contractors recognised by GCP as experienced in the application of GCP products will provide warranties for individual projects. Warranty periods offered are dependent on project details, complexity and GCP products installed. Requests for very long warranty periods may necessitate increased membrane thicknesses to ensure longevity. Contact your local GCP representative for further details.


      Release Date: 30/01/2019. The information contained in this Product Data Sheet supersedes all previous versions. | Australia customer service: 1800 855 525

      Australia 1800 334 444 New Zealand 0800 552 235 China Mainland +86 21 3158 2888 Hong Kong +852 2675 7898 India +91 124 402 8972 Indonesia +62 21 893 4260 Japan +81 3 5226 0231 Korea +82 32 820 0800 Malaysia +60 3 9074 6133 Philippines +63 49 549 7373 Singapore +65 6265 3033 Thailand +66 2 709 4470 Vietnam +84 8 3710 6168

      We hope the information here will be helpful. It is based on data and knowledge considered to be true and accurate, and is offered for consideration, investigation and verification by the user, but we do not warrant the results to be obtained. Please read all statements, recommendations, and suggestions in conjunction with our conditions of sale, which apply to all goods supplied by us. No statement, recommendation, or suggestion is intended for any use that would infringe any patent, copyright, or other third party right.

      BETEC and CRYSTALSEAL are trademarks of GCP Applied Technologies, Inc. This trademark list has been compiled using available published information as of the publication date and may not accurately reflect current trademark ownership or status.

      © Copyright 2019 GCP Applied Technologies, Inc. All rights reserved.

      GCP Applied Technologies Inc., 62 Whittemore Avenue, Cambridge, MA 02140, USA

      Printed in Australia

      This document is only current as of the last updated date stated below and is valid only for use in Australia. It is important that you always refer to the currently available information at the URL below to provide the most current product information at the time of use. Additional literature such as Contractor Manuals, Technical Bulletins, Detail Drawings and detailing recommendations and other relevant documents are also available on Information found on other websites must not be relied upon, as they may not be up-to-date or applicable to the conditions in your location and we do not accept any responsibility for their content. If there are any conflicts or if you need more information, please contact GCP Customer Service.

      Last Updated: 2019-02-14